Low-Pressure H2, NH3 Microwave Plasma Treatment of Polytetrafluoroethylene (PTFE) Powders: Chemical, Thermal and Wettability Analysis
Functionalization of Polytetrafluoroethylene (PTFE) powders of ~6 μm particle size is carried out using low-pressure 2.45 GHz H2, NH3 microwave plasmas for various durations (2.5, 10 h) to chemically modify their surface and alter their surface energy. The X-ray Photoelectron Spectroscopy (XPS) ana...
Main Authors: | , , , , , , |
---|---|
Format: | Article |
Language: | English |
Published: |
MDPI AG
2015-04-01
|
Series: | Materials |
Subjects: | |
Online Access: | http://www.mdpi.com/1996-1944/8/5/2258 |
id |
doaj-90b3943487474597ae57d57e59316771 |
---|---|
record_format |
Article |
spelling |
doaj-90b3943487474597ae57d57e593167712020-11-24T23:07:05ZengMDPI AGMaterials1996-19442015-04-01852258227510.3390/ma8052258ma8052258Low-Pressure H2, NH3 Microwave Plasma Treatment of Polytetrafluoroethylene (PTFE) Powders: Chemical, Thermal and Wettability AnalysisHarald Hunke0Navneet Soin1Tahir H. Shah2Erich Kramer3Alfons Pascual4Mallampalli Sri Lakshmi Karuna5Elias Siores6Institute for Materials Research & Innovation (IMRI), University of Bolton, Deane Road, Bolton BL3 5AB, UKInstitute for Materials Research & Innovation (IMRI), University of Bolton, Deane Road, Bolton BL3 5AB, UKInstitute for Materials Research & Innovation (IMRI), University of Bolton, Deane Road, Bolton BL3 5AB, UKInstitute of Polymer Engineering, University of Applied Sciences (UAS), Northwestern Switzerland, 5210 Windisch, SwitzerlandInstitute of Polymer Engineering, University of Applied Sciences (UAS), Northwestern Switzerland, 5210 Windisch, SwitzerlandCenter for Lipid Research, Indian Institute of Chemical Technology (IICT), Hyderabad 500007, IndiaInstitute for Materials Research & Innovation (IMRI), University of Bolton, Deane Road, Bolton BL3 5AB, UKFunctionalization of Polytetrafluoroethylene (PTFE) powders of ~6 μm particle size is carried out using low-pressure 2.45 GHz H2, NH3 microwave plasmas for various durations (2.5, 10 h) to chemically modify their surface and alter their surface energy. The X-ray Photoelectron Spectroscopy (XPS) analyses reveal that plasma treatment leads to significant defluorination (F/C atomic ratio of 1.13 and 1.30 for 10 h NH3 and H2 plasma treatments, respectively vs. 1.86 for pristine PTFE), along with the incorporation of functional polar moieties on the surface, resulting in enhanced wettability. Analysis of temperature dependent XPS revealed a loss of surface moieties above 200 °C, however, the functional groups are not completely removable even at higher temperatures (>300 °C), thus enabling the use of plasma treated PTFE powders as potential tribological fillers in high temperature engineering polymers. Ageing studies carried over a period of 12 months revealed that while the surface changes degenerate over time, again, they are not completely reversible. These functionalised PTFE powders can be further used for applications into smart, high performance materials such as tribological fillers for engineering polymers and bio-medical, bio-material applications.http://www.mdpi.com/1996-1944/8/5/2258polytetrafluoroethylene (PTFE)low-pressure microwave plasmaESCA/XPSdegenerationthermal stability |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Harald Hunke Navneet Soin Tahir H. Shah Erich Kramer Alfons Pascual Mallampalli Sri Lakshmi Karuna Elias Siores |
spellingShingle |
Harald Hunke Navneet Soin Tahir H. Shah Erich Kramer Alfons Pascual Mallampalli Sri Lakshmi Karuna Elias Siores Low-Pressure H2, NH3 Microwave Plasma Treatment of Polytetrafluoroethylene (PTFE) Powders: Chemical, Thermal and Wettability Analysis Materials polytetrafluoroethylene (PTFE) low-pressure microwave plasma ESCA/XPS degeneration thermal stability |
author_facet |
Harald Hunke Navneet Soin Tahir H. Shah Erich Kramer Alfons Pascual Mallampalli Sri Lakshmi Karuna Elias Siores |
author_sort |
Harald Hunke |
title |
Low-Pressure H2, NH3 Microwave Plasma Treatment of Polytetrafluoroethylene (PTFE) Powders: Chemical, Thermal and Wettability Analysis |
title_short |
Low-Pressure H2, NH3 Microwave Plasma Treatment of Polytetrafluoroethylene (PTFE) Powders: Chemical, Thermal and Wettability Analysis |
title_full |
Low-Pressure H2, NH3 Microwave Plasma Treatment of Polytetrafluoroethylene (PTFE) Powders: Chemical, Thermal and Wettability Analysis |
title_fullStr |
Low-Pressure H2, NH3 Microwave Plasma Treatment of Polytetrafluoroethylene (PTFE) Powders: Chemical, Thermal and Wettability Analysis |
title_full_unstemmed |
Low-Pressure H2, NH3 Microwave Plasma Treatment of Polytetrafluoroethylene (PTFE) Powders: Chemical, Thermal and Wettability Analysis |
title_sort |
low-pressure h2, nh3 microwave plasma treatment of polytetrafluoroethylene (ptfe) powders: chemical, thermal and wettability analysis |
publisher |
MDPI AG |
series |
Materials |
issn |
1996-1944 |
publishDate |
2015-04-01 |
description |
Functionalization of Polytetrafluoroethylene (PTFE) powders of ~6 μm particle size is carried out using low-pressure 2.45 GHz H2, NH3 microwave plasmas for various durations (2.5, 10 h) to chemically modify their surface and alter their surface energy. The X-ray Photoelectron Spectroscopy (XPS) analyses reveal that plasma treatment leads to significant defluorination (F/C atomic ratio of 1.13 and 1.30 for 10 h NH3 and H2 plasma treatments, respectively vs. 1.86 for pristine PTFE), along with the incorporation of functional polar moieties on the surface, resulting in enhanced wettability. Analysis of temperature dependent XPS revealed a loss of surface moieties above 200 °C, however, the functional groups are not completely removable even at higher temperatures (>300 °C), thus enabling the use of plasma treated PTFE powders as potential tribological fillers in high temperature engineering polymers. Ageing studies carried over a period of 12 months revealed that while the surface changes degenerate over time, again, they are not completely reversible. These functionalised PTFE powders can be further used for applications into smart, high performance materials such as tribological fillers for engineering polymers and bio-medical, bio-material applications. |
topic |
polytetrafluoroethylene (PTFE) low-pressure microwave plasma ESCA/XPS degeneration thermal stability |
url |
http://www.mdpi.com/1996-1944/8/5/2258 |
work_keys_str_mv |
AT haraldhunke lowpressureh2nh3microwaveplasmatreatmentofpolytetrafluoroethyleneptfepowderschemicalthermalandwettabilityanalysis AT navneetsoin lowpressureh2nh3microwaveplasmatreatmentofpolytetrafluoroethyleneptfepowderschemicalthermalandwettabilityanalysis AT tahirhshah lowpressureh2nh3microwaveplasmatreatmentofpolytetrafluoroethyleneptfepowderschemicalthermalandwettabilityanalysis AT erichkramer lowpressureh2nh3microwaveplasmatreatmentofpolytetrafluoroethyleneptfepowderschemicalthermalandwettabilityanalysis AT alfonspascual lowpressureh2nh3microwaveplasmatreatmentofpolytetrafluoroethyleneptfepowderschemicalthermalandwettabilityanalysis AT mallampallisrilakshmikaruna lowpressureh2nh3microwaveplasmatreatmentofpolytetrafluoroethyleneptfepowderschemicalthermalandwettabilityanalysis AT eliassiores lowpressureh2nh3microwaveplasmatreatmentofpolytetrafluoroethyleneptfepowderschemicalthermalandwettabilityanalysis |
_version_ |
1725620201311961088 |